Electromagnetically operable valves



Feb. 21, 1967 BENDER T 3,305,209

ELECTROMAGNETICALLY OPERABLE VALVES Filed Dec. 2, 1963 2 Sheets-Sheet 2 ALFRED BENDER HEINZ-DIETER STE E INVENTO BY .lfleslem, Tan 6 Jlaslern United States Patent 3,305,209 ELECTROMAGNETICALLY OPERABLE VALVES Alfred Bender, Hoflleim, Taunus, and Heinz-Dieter Steinke, Frankfurt am Main, Germany, assignors to Alfred Teves Maschinenuud Armaturenfabrik K.G., Frankfurt am Main, Germany, a corporation of Germany Filed Dec. 2, 1963, Ser. No. 327,198 Claims priority, application Germany, Mar. 22, 1963,

8 Claims. (Cl. 25l137) The present invention relates to electromagnetically operable valves and, more particularly, to valves having longitudinally reciprocable valve members displaceable by electromagnetic means.

It has been proposed heretofore to provide electromagnetic valves with magnetically permeable armatures adapted to operate with one or more electromagnets energizable to displace the valve member via the armature coupled therewith between extreme positions against the force of one or more restoring springs. In structures of this type, the restoring springs are not always predictable in their effects and frequently do not ensure that predetermined extreme positions of the valve will be maintained. It has, consequently, been proposed to provide valves of this type with mechanical indexing devices co-operating with the armature or the valve member to retain the latter in the selected extreme position to which it has been displaced by the electromagnetic means. Indexing systems of this character require considerable inductive force to overcome the mechanical inertia of the detent and are unsatisfactory as a consequence of complicated construction and the need for substantially continuous maintenance.

It is, therefore, an object of the present invention to provide an electromagnetically operable valve in which the aforementioned disadvantages can be avoided.

A more specific object of this invention is to provide an electromagnetic valve of this character which does not require restoring or centering springs and in which predetermined operable positions can be maintained without the use of mechanical indexing means.

These objects, and others which will become apparent hereinafter, are attained, in accordance with our present invention, by providing an electromagnetically operable valve for fluid systems in which an armature is coupled with the valve member and co-operates with two longitudinally spaced first electromagnets, the latter forming eleotromagnet means electrically energizable selectively for shifting the armature between two extreme positions. The armature is provided with permanent-magnet means (i.e. a radially polarized permanent magnet surrounding the armature), whose magnetic return is effected via the armature, the magnetically permeable housing surrounding the armature and the electromagnets, and abutment plates at opposite ends of the housing so that this pennanenbmagnet means fonms respective, substantially closed magnetic-flux paths with the armature and the housing for magnetically retaining the armature in each of the extreme positions; To facilitate the displacement of the armature from one extreme position to the other, a pair of second electromagnets (constituting second electromagnet means along the flux path) are juxtaposed with the permanent magnet on opposite sides thereof and are selectively energizable together with respective ones of the first electromagnets for temporarily counteracting the magnetic flux along the respective paths, thereby releasing the armature from magnetic retention in one of the positions and permitting its displacement into the other positions under the inductive force of one of the first electro- 3,305,209 Patented Feb. 21, 1967 "ice magnets. Advantageously, the second electromagnets are so arranged that the one along the completed flux path is energized in parallel with the remote first electromagnet so that the flux along this path is weakened simultaneously with the application of inductive force by the remote first electrom agnet to draw the armature into an extreme position wherein it forms a closed flux path in the region of the energized first electromagnet. The first electromagnets are so constructed as to be at least as strong as the second electromagnets so that the coercive power of the permanent magnet is not disadvantageously influenced by the second electromagnets and the magnetic retention force is fully re-established upon termination of the energizing current.

According to a more particular feature of this invention, the armature of the electromagnet is connected with the longitudinally reciprocable valve member in such manner that the sliding friction of the valve member in the valve body is substantially the only force resisting the inductive force upon joined displacement of the armature and the valve member. We have found it desirable to provide means for preventing rotation of the armature in the housing and the valve member in the valve body; these means may include the connecting pin joining the armature to the valve member. This pin may have a pair of diametrically opposite extensions longitudinally slidable in diametrically opposite recesses formed adjacent the bore of the valve body, at the end thereof proximal to the electrom'agnet housing. The recesses permit the longitudinal displacement of the valve member but are so dimensioned as to angul'arly restrain the latter and the armature. The valve body may be constructed with a sleeve member or lining fixed to the surrounding valve housing, this lining being formed with the bore in which the valve member is longitudinally slidable and the aforementioned recesses. The sleeve member and the valve housing can be provided with at least one inlet and at least one outlet through which a hydraulic fluid can flow when communication is established via longitudinal displacement of the valve member by the electromagnetic means.

The above and other objects, features and advantages of the present invention will become more readily apparent from the following description, reference being made to the accompanying drawing in which:

FIG. 1 is an axial cross-sectional view through a hydraulic distributing valve, according to the present invention, showing a portion of the housing of the electromagnetic means and the armature thereof;

FIG. 2 is a cross-sectional view taken along the line IIII of FIG. 1;

FIG. 3 is an axial cross-sectional view of an electromagnetic system suitable for use with a valve of FIG. 1; and

FIG. 4 is a cross-sectional view taken along the line IV-IV of FIG. 3.

In FIG. 1, we show a valve body comprising a valve housing 1 and a sleeve member 2 threaded into the valve housing and fixed therein in the manner described and claimed in our copending application Ser. No. 327,197, filed concurrently herewith and entitled, Valves (now US. Patent No. 3,211,164). The sleeve member 2 has a longitudinally extending bore in which a slidable, pistonlike valve member 3 is longitudinally reciprocable by electromagnetic means designated generally as 4 via the armature 5 thereof as will become more readily apparent hereinafter. Armature 5 has a terminal portion of reduced cross section received within a blind bore 9 of the valve member 3 and afiixed to the latter by a transverse pin 6 whose length exceeds the diameter of the valve member 3 so that the diametrically projecting extensions 6, 6" of this pin are received within a pair of diametrically opposite recesses 7 wherein the pin 6 is longitudinally guided but restrained from angular motion. Recesses 7 are formed in the face 8 of the valve body proximal to the electromagnetic housing 4.

The valve body 1, 2 is provided with a fluid-tight cap 26 and an O-ring seal 27 at its end remote from the electromagnetic housing to prevent escape of fiuid between the sleeve member 2 and the valve member 3 during operation of the valve. An inlet bore 10 is provided in the valve body 1, 2 to supply hydraulic fluid from a pump 23 and a reservoir 22 to an annular groove 14 constituting the pressure compartment within the valve.

Similarly, an outlet bore .11 is provided in the valve body and connected with a hydraulically operable mechanism 24, such as a hydraulic cylinder While a further bore 12 is connected via return conduit 25 to the reservoir 22. Bores 11 and 12 communicate respectively with annular grooves 15 and 16 while a further bore 13 communicates when an annular compartment 17 through which any hydraulic fluid escaping toward the right-hand end of the valve body is diverted to the reservoir or sump 2 2. Annular compartments 19 and 20, formed by reduced-diameter portions of the valve member 3 alternately connect the pressure compartment 14 with the working compartment 15 to energize the hydraulic cylinder 24 and the working compartment 15 with the reservoir outlet 16 whereby fluid is drained from the hydraulic cylinder 24 to the reservoir 22.

In the position of the valve shown in FIG. 1, pressure compartment .14 communicates with the working compartment 15 via chamber 19 while the overlap of edges 21 and 2-2 of the sleeve member 2 and the valve member 3 respectively, prevents fiow of fluid into the return passage 19. When the valve member 3 is shifted to the left, however, compartment 19 is blocked while communication is established via chamber 20 from the working compartment 15 to the return compartment 16.

Referring now to FIGS. 3 and 4, it may be seen that the armature has an enlarged portion 5 which is received within the electromagnet housing 4. The latter comprises a pair of end plates 28, 29 affixed by bolts 30 to a magnetically permeable shell 31. The shell has secured thereto pole pieces 32, 33 defining the extreme positions of the armature. The armature 5 carries a radially polarized annular permanent magnet 40 which, in its right-hand position illustrated in FIG. 3 for-ms a closed magnetic flux path (dot-dash line 38) along the armature 5, pole pieces 33, magnetic shell 31 and end plate 29.

A pair of first electromagnets 36, 37 are fixed within the housing 4 and serve to displace the armature 5 between its extreme positions. Additionally, a pair of second electromagnets 34, 35 are juxtaposed with the permanent magnet 40 and serve for reducing the flux of the path and facilitating displacement of the armature from one position to another. Magnet 34 is connected in parallel with electromagnet 37 while electromagnet 35 is in parallel with electromagnet 36. When the device is in the position illustrated in FIG. 3, an electrical impulse supplied to the electromagnets 37 and 34 will simultaneously cause the formation of counteracting flux .lines 39 to reduce the magnetic retaining force holding permanent magnet 40 in line with pole pieces 33 and provide an axial inductive force along the armature 5 in a direction away from the energized second electromagnet 34 to shift this armature and the valve member 3 secured thereto into its extreme left-hand position, the latter being defined upon alignment of permanent magnet 40 with pole pieces 32 and abutment of the enlarged portion 5' of the armature with plate 28 to establish a new closed magnetic fiux path extending through this armature, permanent magnet 40, pole pieces 32, magnetically permeable shell 31 and plate 28. The extreme left-hand position may also be defined by abutment of the pin 6 against the end of recess 7. When an impulse is provided to electromagnet 35 and 36, the fiux holding the permanent magnet 40 in position relative to pole pieces 32 is weakened and the inductive force of magnetic coil 36 draws the armature 35 to the right. It will be apparent that electromagnets 34, 35 can be mounted upon the armature 5 or otherwise disposed in proximity to the faces of the permanent magnet 40. The apparatus illustrated in FIGS. 1 and 3 provides valve operation without the use of mechanical indexing means or restoring springs and insures that only friction forces within the valve will resist the induction forces moving the displaced armature 5 upon energization of one or the other set of coils.

The invention described and illustrated is believed to admit of many modifications within the ability of persons skilled in the art, all such modifications being considered within the spirit and scope of the appended claims.

We claim:

1. An electromagnetic actuating device, comprising a magnetically permeable housing;

a longitudinally extending armature of magnetically permeable material connectable to a member to be actuated and reciprocable in said housing between two extreme positions;

permanent-magnet means on said armature forming substantially closed magnetic-flux paths with said armature and said housing for magnetically retaining said armature in each of said extreme positions;

a pair of longitudinally spaced first electromagnets in said housing on opposite sides of said permanent-magnet means cooperating with said armature upon selective electrical energization for shifting said armature between said extreme positions; and

a pair of second electromagnets juxtaposed with said permanent-magnet means on opposite sides thereof along said paths and selectively energizable concurrently with at least one of said first electromagnets for temporarily counteracting the magnetic flux along a respective one of said paths for releasing said armature from one of said positions and permitting its displacement into the other of said positions under the inductive force of said one of said first electromagnets.

2. An electromagnetic actuating device, comprising a magnetically permeable housing;

a longitudinally extending armature of magnetically permeable material connectable to a member to be actuated and reciprocable in said housing between two extreme positions;

a radially polarized permanent magnet surrounding said armature and forming respective substantially closed magnetic-flux paths with said armature and said housing for magnetically retaining said armature in each of said extreme positions;

first electromagnet means in said housing cooperating with said armature upon electrical energization for shifting said armature between said extreme positions; and

a pair of second electromagnets juxtaposed with said permanent magnet on opposite sides thereof along said paths and selectively energizable concurrently with said first electromagnet means for temporarily counteracting the magnetic fiux alon a respective one of said paths for releasing said armature from one of said positions and permitting its displacement into the other of said positions under the inductive force of said first electromagnet means.

3. An electromagnetic actuating device, comprising a magnetically permeable housing;

a longitudinally extending armature of magnetically permeable material connectable to a member to be actuated and reciprocable in said housing between two extreme positions;

a radially polarized permanent magnet surrounding said armature and forming respective substantially closed magnetic-flux paths with said armature and said housing for magnetically retaining said armature in each of said extreme positions;

a pair of longitudinally spaced first electromagnets in said housing on opposite sides of said permanent magnet cooperating with said armature upon selective electrical energization for shifting said armature between said extreme positions; and

a pair of second electromagnets juxtaposed with said permanent magnet on opposite sides thereof along said path and selectively energizable concurrently with at least one of said first electromagnets for temporarily counteracting the magnetic flux along a respective one of said paths for releasing said armature from one of said positions and permitting its displacement into the other of said positions under the inductive force of said one of said first electromagnets.

4. An electromagnetic actuating device, magnetically permeable housing;

'a longitudinally extending armature of magnetically permeable material connectable to a member to be actuated and reoiprocable in said housing between two extreme positions;

a radially polarized permanent magnet surrounding said said armature and forming respective substantially closed magnetic-flux paths with said armature and said housing for magnetically retaining said armature in each of said extreme positions;

first electromagnetic means in said housing cooperating with said armature upon electrical energization for shifting said armature between said extreme positions;

a pair of second electromagnets juxtaposed with said permanent magnet on opposite sides thereof along said paths and selectively energizable concurrently with said first electromagnet means for temporarily counteracting the magnetic flux along a respective one of said paths for releasing said armature from one of said positions and permitting its displacement into the other of said positions under the inductive force of said first electromagnet means;

means for preventing rotation of said armature in said housing and of said member.

5. An electromagnetic actuating device for a valve having a longitudinally reciprocable valve member, and a valve body surrounding said valve member and slidably receiving same for communicating between a fluid inlet and a fluid outlet formed in said body, said actuating device comprising:

a magnetically permeable housing;

a longitudinally extending armature of magnetically permeable material connected with said member and reciprocable in said housing between two extreme positions;

comprising a a radially polarized permanent magnet surrounding said armature and forming respective substantially closed magnetic-flux paths with said armature and said housing for magnetically retaining said armature in each of said extreme positions;

a pair of longitudinally spaced first electromagnets in said housing on opposite sides of said permanent magnet cooperating with said armature upon selec tive electrical energization for shifting said armature between said extreme positions;

a pair of second electromagnets juxtaposed with said permanent magnet on opposite sides thereof alOng said paths and selectively energizable concurrently with at least one of said first electromagnets for temporarily counteracting the magnetic flux along a respective one of said paths for releasing said armature from one of said positions and permitting its displacement into the other of said positions under the inductive force of said one of said first electromagnets, the sliding friction of said valve member in said body being substantially the only force resisting said (inductive force upon joint displacement of said armature and said member; and

means for preventing rotation of said armature in said housing and said valve member in said body.

6. An actuating device as defined in claim 5 wherein said valve body is fixed to said housing, said armature being connected to said valve member by a transversely extending pin.

7. An actuating device as defined in claim 6 wherein said valve body is formed with a longitudinally extending bore and a pair of diametrically opposite recesses adjacent said bore at an end thereof proximal to said housing, said means for preventing rotation of said armature and said valve member including extensions of said pin longitudinally displaceable in said recesses but angularly restrained thereby.

8. An actuating device as defined in claim 7 wherein said valve body comprises a valve housing and a sleeve member fixed in said valve housing and provided with said bore and said recesses, said magnetically permeable housing being axially aligned with said valve housing, and said valve member being axially aligned with said armature.

References Cited by the Examiner UNITED STATES PATENTS 1,090,902 3/1914 BeckWith 251137 3,126,501 3/1964 Flora 317171 X 3,178,151 4/1965 Caldwell 251-137 3,202,886 8/1965 Kramer 317-171 M. CARY NELSON, Primary Examiner.

R. C. MILLER, Assistant. 

1. AN ELECTROMAGNETIC ACTUATING DEVICE, COMPRISING A MAGNETICALLY PERMEABLE HOUSING; A LONGITUDINALLY EXTENDING ARMATURE OF MAGNETICALLY PERMEABLE MATERIAL CONNECTABLE TO A MEMBER TO BE ACTUATED AND RECIPROCABLE IN SAID HOUSING BETWEEN TWO EXTREME POSITIONS; PERMANENT-MAGNET MEANS ON SAID ARMATURE FORMING SUBSTANTIALLY CLOSED MAGNETIC-FLUX PATHS WITH SAID ARMATURE AND SAID HOUSING FOR MAGNETICALLY RETAINING SAID ARMATURE IN EACH OF SAID EXTREME POSITIONS; A PAIR OF LONGITUDINALLY SPACED FIRST ELECTROMAGNETS IN SAID HOUSING ON OPPOSITE SIDES OF SAID PERMANENT-MAGNET MEANS COOPERATING WITH SAID ARMATURE UPON SELECTIVE ELECTRIC ENERGIZATION FOR SHIFTING SAID ARMATURE BETWEEN SAID EXTREME POSITIONS; AND A PAIR OF SECOND ELECTROMAGNETS JUXTAPOSED WITH SAID PERMANENT-MAGNET MEANS ON OPPOSITE SIDES THEREOF ALONG SAID PATHS AND SELECTIVELY ENERGIZABLE CONCURRENTLY WITH AT LEAST ONE OF SAID FIRST ELECTROMAGNETS FOR TEMPORARILY COUNTERACTING THE MAGNETIC FLUX ALONG A RESPECTIVE ONE OF SAID PATHS FOR RELEASING SAID ARMATURE, FROM ONE OF SAID POSITIONS AND PERMITTING ITS DISPLACEMENT INTO THE OTHER OF SAID POSITIONS UNDER THE INDUCTIVE FORCE OF SAID ONE OF SAID FIRST ELECTROMAGNETS. 